When you first head down the road of defining a possible issue with gluten, it’s like entering a new dimension. And you also need to learn a new vocabulary to navigate that world. You’ve been lucky enough to find a doctor who is associating your potentially varied symptoms with celiac disease, and now you need to be concerned about how your lab results are being analyzed, or you may be given a mistakenly clean bill of health.
In order to achieve what physicians call the “gold standard” of a celiac disease diagnosis, an endoscopy must be done that shows histological changes, or damage, to the small bowel. The villi that line the small intestine are like what you would think of as a deep, thick, dense-pile carpet. Each of the villi can be compared to a carpet thread, contributing it’s surface area (imagine going up one side of the thread, across the tip and down the other side) to the absorption of nutrients during digestion. However, when the villi encounter something that they cannot absorb, such as the gliadin protein in the case of celiac disease, they become damaged and show signs of decreased length, referred to as villous atrophy. Additionally, there are cellular changes, such as increased lymphocytes in the tips of the villi, that indicate inflammation. See these photos from TheFoodDoc.com to gain a better understanding of what this looks like under a microscope. So now your beautiful thick carpet of villi has worn down patches and ratty areas that make your intestinal lining look like crackled dried out mud. You may think, “Why should I care what it looks like in there, the doctor and the lab guy know what they’re doing.” But is that really the truth?
From the Journal of Clinical Pathology, 2011 we learn that biopsies, or tissue samples taken during the endoscopy procedure, are subject to “interobserver variability”, meaning that different pathology practices may be reading biopsies differently.
Biopsies from community hospitals, university hospitals and commercial laboratories were blindly assessed by a pathologist at our institution for differences in histopathology reporting and agreement in diagnosis of CD [celiac disease] and degree of villous atrophy (VA) by κ analysis.
The results were that the agreement for primary diagnosis was very good at the university hospitals, but not nearly so good at community hospitals and commercial laboratories. Actual diagnosis differed in 25% of cases, which meant that after the cases were reviewed, there was a 20% increase in celiac disease diagnosis! Even the degree of villous atrophy, damage or blunting of the villi, was upgraded in 27% of cases. And when it came to the really subtle early stages of damage that are categorized as Marsh scores, there were complete misses at the community hospitals and commercial labs, where they only began to pick up on the details when the damage became more significant. Some labs used only basic descriptions like blunting or marked atrophy when referring to damage as opposed to providing degree of villous atrophy and IEL’s (intraepitheilial lymphocytosis) counts, or even left the information out altogether.
The intraepithelial lymphocytes are white blood cells that are part of the immune response to the proteins in food that are causing the damage. The lymphocytes rise to the surface of the lining, displacing enterocytes which are usually there, absorbing your nutrients. The IEL count may need to be analyzed in the lab through the use of a special immune chemistry stain that can make normal looking tissue reveal higher counts of lymphocytes. This can be extremely beneficial to diagnose the earliest signs of injury to the intestine, for people who already might have, with the best intentions, restricted gluten in their diets, and family members of people who have celiac disease. Catching the disease at this early stage can greatly reduce the amount of damage to the gut.
So when you’re dealing with a celiac disease diagnosis, a university lab might be your best setting. If that’s not possible, ask your doctor about what lab he will be sending your biopsies to, and what type of standards they are using to analyze the tissue. It could make the difference between a correct diagnosis, and living with the ongoing damage of celiac disease that they are now “sure” you don’t have because the lab said so.